So if nuclear ever became a staple, you'd end up needing to resort to salt-water extraction, or developing breeder reactors. Both would send costs skyrocketing. Salt-water extraction is also going to run into environmental issues given you're talking about processing literally trillions of tons of water (uranium's about 3 parts per billion in saltwater). Breeders also substantially up the stakes in terms of complexity and risk.
If you'd indulge my curiosity, what would be your opposition be to something like solar + artificial hydroelectric? It's relatively cheap, infinite (well subject to access to the materials necessary for construction of solar panels), completely safe in any scenario, and things like artificial hydroelectric take care of the biggest issue of day/night production.
[1] - https://www.scientificamerican.com/article/how-long-will-glo...
Anyhow, nuclear power plants are in them self a major national security weakness. Especially with these put small reactor everywhere cracy talk. But then again "national security" is about "security" about as much how the "defense industry" is about "defence".
I sometimes feel that nuclear power is a proxy discussion for something else that is also not very popular among the voters. It kinda makes sense if you just replace "power" with "war".
So nuclear starts to look very attractive because of the guarantee of continual high power output with few dependencies as long as you have the uranium, and isn't as unreliable as renewables.